Wrist implant apparatus and method

1. A prosthetic wrist implant comprising:

(a) a radial component including a base member having an upper bearing surface and a lower surface having an elongated radial stem extending therefrom for fixation to a radius bone;

(b) a carpal component including a substantially planar base member having an upper surface having an elongated carpal post member for fixation to one or more carpal bones, an outer edge, and a lower surface with at least one socket protrusion extending therefrom;

(c) an articulating bearing component for placement between the radial and carpal components, the bearing component having an upper surface defining at least one socket recess having a continuous inner circumference and a lower bearing surface for cooperative engagement with the upper bearing surface of the radial component; and

(d) wherein the socket protrusion of the carpal component is configured for linearly and coaxially engaging the socket recess of the bearing component to minimize rotational and translational movement of the carpal component relative to the bearing component.

2. The prosthetic wrist implant according to claim 1 wherein the elongated radial stem of the radial component is in an off-center position in relation to a center of the lower surface of the radial component.

3. A prosthetic wrist implant comprising:

(a) a radial component including a base member having an upper bearing surface and a lower surface having an elongated radial stem extending therefrom for fixation to a radius bone;

(b) a carpal component including a substantially planar base member having an upper surface having an elongated carpal post member for fixation to one or more carpal bones, an outer edge, and a lower surface with at least one socket protrusion extending therefrom;

(c) an articulating bearing component for placement between the radial and carpal components, the bearing component having an upper surface defining at least one socket recess and a lower bearing surface for cooperative engagement with the upper bearing surface of the radial component;

wherein the socket protrusion of the carpal component is adapted to linearly engage the socket recess of the bearing component to desirably limit rotational and translational movement of the carpal component relative to the bearing component; and

wherein the articulating bearing component further comprises a substantially continuous extended skirt of material around the perimeter of and extending from the upper surface of the bearing component, the extended skirt further defining a skirt upper edge furthest away from the upper surface.

4. The prosthetic wrist implant according to claim 3 wherein the skirt at least substantially surrounds the carpal component planar base member outer edge when the socket protrusion of the carpal component is engaged with the socket recess of the bearing component.

5. The prosthetic wrist implant according to claim 4 wherein the skirt upper edge is disposed upon a plane that is substantially coplanar with the carpal component planar base member upper surface.

6. A prosthetic wrist implant comprising:

(a) a radial component including a base member having an upper bearing surface and a lower surface having an elongated radial stem extending therefrom for fixation to a radius bone;

(b) a carpal component including a substantially planar base member having an upper surface having an elongated carpal post member for fixation to one or more carpal bones, an outer edge, and a lower surface with at least one socket protrusion extending therefrom;

(c) an articulating bearing component for placement between the radial and carpal components, the bearing component having an upper surface defining at least one socket recess and a lower bearing surface for cooperative engagement with the upper bearing surface of the radial component;

wherein the socket protrusion of the carpal component is adapted to linearly engage the socket recess of the bearing component to desirably limit otational and translational movement of the carpal component relative to the bearing component; and

wherein the upper bearing surface of the radial component is at least substantially concave.

7. The prosthetic wrist implant according to claim 6 wherein the lower bearing surface of the bearing component is at least substantially convex in proportional relationship to the substantially concaved upper bearing surface of the radial component.

8. A prosthetic wrist implant comprising:

(a) a radial component including a base member having an upper bearing surface and a lower surface having an elongated radial stem extending therefrom for fixation to a radius bone;

(b) a carpal component including a substantially planar base member having an upper surface having an elongated carpal post member for fixation to one or more carpal bones, an outer edge, and a lower surface with at least one socket protrusion extending therefrom;

(c) an articulating bearing component for placement between the radial and carpal components, the bearing component having an upper surface defining at least one socket recess and a lower bearing surface for cooperative engagement with the upper bearing surface of the radial component;

wherein the socket protrusion of the carpal component is adapted to linearly engage the socket recess of the bearing component to desirably limit rotational and translational movement of the carpal component relative to the bearing component; and

wherein the socket protrusion of the carpal component is substantially cylindrical and further comprises an external lip that is continuous around the circumference of the socket protrusion.

9. The prosthetic wrist implant according to claim 8 wherein the socket recess of the bearing component is substantially cylindrical and further comprises an internal groove that is continuous around the circumference of the socket recess.

10. The prosthetic wrist implant according to claim 9 wherein the upper surface of the articulating bearing component is attached to the planar base member lower surface of the carpal component by an external lip of the socket protrusion of the carpal component matingly engaging an internal groove of the socket recess of the bearing component.

11. The prosthetic wrist implant according to claim 1 wherein the articulating bearing component is constructed of a plastic material.

12. The prosthetic wrist implant according to claim 1 wherein the lower surface of the radial component has a first substantially flat portion and a second substantially flat portion disposed at an angle with respect to the first flat portion.

13. The prosthetic wrist implant according to claim 1 wherein the elongated radial stem of the radial component is fixated to the radius bone through the use of bone cement.

14. The prosthetic wrist implant according to claim 1 wherein the elongated radial stem of the radial component is fixated to the radius bone through press-fitting.

15. A prosthetic wrist implant comprising:

(a) a radial component including a base member having an upper bearing surface and a lower surface having an elongated radial stem extending therefrom for fixation to a radius bone;

(b) a carpal component including a substantially planar base member having an upper surface having an elongated carpal post member for fixation to one or more carpal bones, an outer edge, and a lower surface with a pair of socket protrusions extending therefrom, wherein each socket protrusion defines an opening therethrough adapted for receiving a screw;

(c) an articulating bearing component for placement between the radial and carpal components, the bearing component having an upper surface defining a pair of socket recesses having continuous inner circumferences, and the bearing component having a lower bearing surface for cooperative engagement with the upper bearing surface of the radial component; and

(d) wherein the pair of socket protrusions of the carpal component is configured for linearly and coaxially engaging the pair of socket recesses of the bearing component to minimize rotational and translational movement of the carpal component relative to the bearing component.

16. The prosthetic wrist implant according to claim 15 wherein the elongated radial stem of the radial component is in an off-center position in relation to a center of the lower surface of the radial component.

17. A prosthetic wrist implant comprising:

(a) a radial component including a base member having an upper bearing surface and a lower surface having an elongated radial stem extending therefrom for fixation to a radius bone;

(b) a carpal component including a substantially planar base member having an upper surface having an elongated carpal post member for fixation to one or more carpal bones, an outer edge, and a lower surface with a pair of socket protrusions extending therefrom, wherein each socket protrusion defines an opening therethrough adapted for receiving a screw;

(c) an articulating bearing component for placement between the radial and carpal components, the bearing component having an upper surface defining a pair of socket recesses, and the bearing component having a lower bearing surface for cooperative engagement with the upper bearing surface of the radial component;

wherein the pair of socket protrusions of the carpal component is adapted to linearly engage the pair of socket recesses of the bearing component to desirably limit rotational and translational movement of the carpal component relative to the bearing component; and

wherein the articulating bearing component further comprises a substantially continuous extended skirt of material around the perimeter of and extending from the upper surface of the bearing component, the extended skirt further defining a skirt upper edge furthest away from the upper surface.

18. The prosthetic wrist implant according to claim 17 wherein the skirt at least substantially surrounds the carpal component planar base member outer edge when the socket protrusion of the carpal component is engaged with the socket recess of the bearing component.

19. The prosthetic wrist implant according to claim 18 wherein the skirt upper edge is disposed upon a plane that is substantially coplanar with the carpal component planar base member upper surface.

20. A prosthetic wrist implant comprising:

(a) a radial component including a base member having an upper bearing surface and a lower surface having an elongated radial stem extending therefrom for fixation to a radius bone;

(b) a carpal component including a substantially planar base member having an upper surface having an elongated carpal post member for fixation to one or more carpal bones, an outer edge, and a lower surface with a pair of socket protrusions extending therefrom, wherein each socket protrusion defines an opening therethrough adapted for receiving a screw;

(c) an articulating bearing component for placement between the radial and carpal components, the bearing component having an upper surface defining a pair of socket recesses, and the bearing component having a lower bearing surface for cooperative engagement with the upper bearing surface of the radial component;

wherein the pair of socket protrusions of the carpal component is adapted to linearly engage the pair of socket recesses of the bearing component to desirably limit rotational and translational movement of the carpal component relative to the bearing component; and

wherein the upper bearing surface of the radial component is at least substantially concave.

21. The prosthetic wrist implant according to claim 20 wherein the lower bearing surface of the bearing component is at least substantially convex in proportional relationship to the substantially concaved upper bearing surface of the radial component.

22. A prosthetic wrist implant comprising:

(a) a radial component including a base member having an upper bearing surface and a lower surface having an elongated radial stem extending therefrom for fixation to a radius bone;

(b) a carpal component including a substantially planar base member having an upper surface having an elongated carpal post member for fixation to one or more carpal bones, an outer edge, and a lower surface with a pair of socket protrusions extending therefrom, wherein each socket protrusion defines an opening therethrough adapted for receiving a screw;

(c) an articulating bearing component for placement between the radial and carpal components, the bearing component having an upper surface defining a pair of socket recesses, and the bearing component having a lower bearing surface for cooperative engagement with the upper bearing surface of the radial component;

wherein the pair of socket protrusions of the carpal component is adapted to linearly engage the pair of socket recesses of the bearing component to desirably limit rotational and translational movement of the carpal component relative to the bearing component; and

wherein the socket protrusion of the carpal component is substantially cylindrical and further comprises an external lip that is continuous around the circumference of the socket protrusion.

23. The prosthetic wrist implant according to claim 22 wherein the socket recess of the bearing component is substantially cylindrical and further comprises an internal groove that is continuous around the circumference of the socket recess.

24. The prosthetic wrist implant according to claim 23 wherein the upper surface of the articulating bearing component is attached to the planar base member lower surface of the carpal component by an external lip of the socket protrusion of the carpal component matingly engaging an internal groove of the socket recess of the bearing component.

25. The prosthetic wrist implant according to claim 15 wherein the articulating bearing component is constructed of a plastic material.

26. The prosthetic wrist implant according to claim 15 wherein the lower surface of the radial component has a first substantially flat portion and a second substantially flat portion disposed at an angle with respect to the first flat portion.

27. The prosthetic wrist implant according to claim 15 wherein the elongated radial stem of the radial component is fixated to the radius bone through the use of bone cement.

28. The prosthetic wrist implant according to claim 15 wherein the elongated radial stem of the radial component is fixated to the radius bone through press-fitting.

29. A prosthetic wrist implant for implantation between a patient's radius bone and carpal bone complex comprising:

(a) a radial component including a base member having an upper bearing surface and a lower surface having an elongated radial stem extending therefrom that is implanted into a radius bone;

(b) a carpal component including a substantially planar base member having an upper surface having an elongated carpal post member that is implanted into the capitate bone of the carpal bone complex, a lower surface with a pair of socket protrusions extending therefrom, wherein each socket protrusion defines an opening therethrough adapted for receiving a screw, and further wherein a screw is implanted into the trapezoid bone and another screw is implanted into the hamate bone of the carpal bone complex;

(c) an articulating bearing component for placement between the radial and carpal components, the bearing component having an upper surface defining a pair of socket recesses having continuous inner circumferences, and the bearing component having a lower bearing surface for cooperative engagement with the upper bearing surface of the radial component; and

(d) wherein the pair of socket protrusions of the carpal component is configured for linearly and coaxially engaging the pair of socket recesses of the bearing component to minimize rotational and translational movement of the carpal component relative to the bearing component.

30. The prosthetic wrist implant according to claim 29 wherein the elongated radial stem of the radial component is in an off-center position in relation to a center of the lower surface of the radial component.

31. A prosthetic wrist implant system comprising:

(a) a plurality of different sized radial components, each radial component including a base member having an upper bearing surface and a lower surface having an elongated radial stem extending therefrom for fixation to a radius bone;

(b) a plurality of different sized carpal components, each carpal component including a substantially planar base member having an upper surface having an elongated carpal post member for fixation to one or more carpal bones and a lower surface with at least one socket protrusion extending therefrom;

(c) a plurality of different sized articulating bearing components for placement between correspondingly sized radial and carpal components, each bearing component having an upper surface defining at least one socket recess having a continuous inner circumference and a lower bearing surface for cooperative engagement with the upper bearing surface of a correspondingly sized radial component; and

(d) wherein the socket protrusion of the selected carpal component is configured for linearly and coaxially engaging the socket recess of a correspondingly sized bearing component to minimize rotational and translational movement of the carpal component relative to the bearing component.

32. The prosthetic wrist implant system according to claim 31 wherein the elongated radial stem of the radial component is in an off-center position in relation to a center of the lower surface of the radial component.